This invention relates to hydraulic controls for articulating and raising hospital beds and more particularly to a hydraulic control apparatus which uses solenoid valves and an electric pump which can be overridden by manual controls and a manual pump.
It is well known for patient support devices such as hospital beds and stretchers to be provided with hydraulic systems which allow the caregiver to raise the height of the bed and articulate a deck underlying the patient support surface to modify the configuration of the patient support surface. When such beds were originally conceived, the control valves and pumps associated with hydraulic cylinders were all manually operated. Manual operation of pumps and control valves can become fatiguing, therefore, articulatable and height adjustable beds were provided with electric motors and electrically controlled valves associated with the hydraulic cylinders. Combinations of electrically controlled pumps and valves and manually operated pumps and valves are also known. One problem with electrically controlled hydraulic cylinders is that during power outages the cylinder cannot be operated and the bed cannot be adjusted. Height adjustment and bed articulation facilitate appropriate treatment of patient injuries, and therefore, loss of the articulation and height adjustment is undesirable in a hospital environment.
Hospital beds with adjustable patient support surfaces moved by hydraulic cylinders which can be controlled either manually or electrically have been provided to address the need for bed adjustment in the event of a power outage. Smith et al., U.S. Pat. No. 5,063,624, discloses a manual/electric twin jack bed which provides for manual or electric control of valves and pumps for providing fluids to hydraulic cylinders which will adjust the height of the bed and allow the bed to be configured in Trendelenburg and Reverse Trendelenburg positions.
Bailey et al., U.S. Pat. No. 4,751,754, discloses a dual hydraulic hospital bed with emergency bypass circuit which provides manually actuated valves and electrically actuated valves for controlling hydraulic cylinders which raise, lower, and articulate a patient support platform. Both of these dually controlled hydraulic systems appear to use a different set of valves for manual operation and electrical operation of the hydraulic systems. Thus, the hydraulic controls could not easily be retrofitted to a bed previously having only a manual or only an electrically controlled hydraulic system.
Caregivers would appreciate a hydraulic control apparatus for a hospital bed that includes a hilow function and an articulating deck which can be operated manually, electrically, or through a combination of manual and electric operation using a single set of valves. Caregivers and healthcare facilities would appreciate a hydraulic control system allowing manual and electrical operation which could replace the controller on a bed which was operated with only manual controls or only with electrical controls.
According to the present invention a manifold and valve assembly includes a manifold block having an inlet, an outlet, and a conduit in fluid communication with the inlet and with the outlet, a valve having a portion movable within the conduit between a first position blocking fluid communication between the inlet and the outlet and a second position in which the inlet is in fluid communication with the outlet, a solenoid operable to move the valve from the first position to the second position in response to an electrical input applied to the solenoid, and a lever operable to move the valve from the first position to the second position in response to a manual input applied to the lever. The manifold and valve assembly may also include a lock engaging the lever to lock the lever in a position having the valve in the second position. The lock may include a lock solenoid and a lock bar coupled to the lock solenoid, wherein the lock bar engages the lever, and the lock solenoid is operable to move the lock bar in response to an electrical input to the lock solenoid. Often the lever is pivotally coupled to the manifold block and the solenoid is positioned to lie between the manifold block and the lever. The valve may include a stem a part of which is received in an opening in the lever.
According to the present invention a controller for a hospital bed having a bed frame and a support section arranged to receive a portion of a patient""s body which is vertically movable with respect to the frame includes a fluid actuated cylinder attached between the support section and the bed frame, a supply of fluid, a fluid supply path providing fluid communication between the fluid supply and the fluid actuated cylinder, a manually operated pump in the fluid supply path, an electrically operated pump in the fluid supply path, a valve block having a solenoid operated supply valve with manual override in the fluid supply path and designed to selectively interrupt the fluid supply path, an electrical supply actuator connected to the solenoid of the supply valve and to the electrically operated pump to electrically control the interruption of fluid communication between the fluid actuated cylinder and the fluid supply, and a manual actuator connected to the manual override of the supply valve to manually control the interruption of fluid communication between the fluid actuated cylinder and the fluid supply. The controller may also include an electrically actuated manual setting remover coupled to the electrical actuator so that the manual setting is removed upon electrical actuation of the solenoid of the valve. The controller may include a fluid return path providing fluid communication between the fluid supply and the fluid actuated cylinder, a solenoid operated return valve with manual override to selectively interrupt fluid communication between the fluid actuated cylinder and the fluid return path, and an electrical control including the electrical supply actuator and an electrical return actuator connected to the solenoid of the return valve to electrically control the interruption of fluid return path arranged so that the manual supply actuator is also connected to the manual override of the return valve to manually control the interruption of fluid return path.
A valve block in accordance with the present invention includes a fluid supply path, a fluid return path, a valve assembly having a supply member and a return member, a multi-state manual actuator operably connected to the supply member and the return member, an electrical actuator operably connected to the supply member and to the return member, a controller for generating an override signal when the electrically operated actuator is actuated, and a manual actuator override. The supply member of the valve assembly is positionable between a supply interruption position in which the supply member interrupts the fluid supply path and a supply position in which the supply member does not interrupt the fluid supply path while the return member is positionable between a return interruption position in which the return member interrupts the fluid return path and a return position in which the return member does not interrupt the fluid return path. The multi-state manual actuator is designed and arranged to assume a supply state in which the supply member is in the supply position and the return member is in the return interruption position, a return state in which the return member is in the return position and the supply member is in the supply interruption position, and a neutral state wherein the supply member and the return member are free to assume any position. The electrical actuator selectively positions the supply member between the supply interruption position and the supply position and also selectively positions the return member between the return interruption position and the return position. The manual actuator override is designed and arranged to place the multi-state manual actuator in the neutral state when an override signal is generated.
The valve assembly may include a supply valve and a spaced apart return valve. The supply member may include a supply-opened engagement point and the return member may include a return-opened engagement point and the multi-state manual actuator may include an arm which engages the supply-opened engagement point and does not engage the return-opened engagement point when the multi-state manual actuator is in the supply state, engages the return-opened engagement point and does not engage the supply-opened engagement point when the multi-state manual actuator is in the return state, and does not engage either the supply-opened or return-opened engagement points when in the neutral position. The multi-state manual actuator may include a spring element biasing it in the neutral state, a supply state catch to lock it in the supply state, and a return state catch to lock it in the return state. The override may include a catch engager and a catch engager actuator to position the catch engager between a catch-engaged state in which it engages either the supply catch or the return catch and a catch-disengaged state. The catch engager actuator may include an arm biased to engage either the supply catch or the return catch and a solenoid electromagnetically coupled to the arm to disengage the arm from the supply catch or the return catch when the solenoid is energized. The interrupt signal may cause the solenoid to be energized. The valve assembly may include a supply valve and a spaced apart return valve. The valve block may also include a housing having a mounting surface, and a fulcrum having a first side and a second side mounted to the mounting surface, wherein the arm is pivotally mounted to the fulcrum and the supply valve is mounted to the mounting surface on the first side of the fulcrum and the return valve is mounted to the mounting surface on the second side of the fulcrum.
A control for a hospital bed having a bed frame, a first support section arranged to receive a first portion of a patient""s body and being vertically movable with respect to the frame, and a second support section arranged to support a second portion of a patient""s body in accordance with the present invention includes a first fluid actuated cylinder attached between the first support section and the bed frame, a second fluid actuated cylinder attached between the second support section and the bed frame, a supply of fluid, a fluid return path, fluid supply path, a manually operated pump, an electrically operated pump, a valve block including a first valve assembly and a second valve assembly, and a valve controller connected to the first valve assembly and the second valve assembly. The return fluid path provides fluid communication between the fluid supply and the cylinders while the fluid supply path provides fluid communication between the fluid supply and the cylinders. Both the manually operated pump and the electrically operated pump are in fluid communication with the fluid supply path. The first valve assembly is in fluid communication with the first fluid actuated cylinder, the fluid supply path, and the fluid return path. The first valve assembly is designed to selectively interrupt fluid communication between the first fluid actuated cylinder and the fluid supply path and to selectively interrupt fluid communication between the first fluid actuated cylinder and the fluid return path. The second valve assembly is in fluid communication with the second fluid actuated cylinder, the fluid supply path, and the fluid return path. The second valve assembly is designed to selectively interrupt fluid communication between the second fluid actuated cylinder and the fluid supply path and to selectively interrupt fluid communication between the second fluid actuated cylinder and the fluid return path. The valve controller controls the interruption of fluid communication between the first fluid actuated cylinder and the fluid supply path, the first fluid actuated cylinder and the fluid return path, the second fluid actuated cylinder and the fluid supply path, and the second fluid actuated cylinder and the fluid return path. The valve controller is designed to prohibit the first valve assembly from assuming a state in which fluid communication is simultaneously not interrupted between the first fluid actuated cylinder and the fluid return path and the first actuated cylinder and the fluid supply path and to prohibit the second valve assembly from assuming a state in which fluid communication is simultaneously not interrupted between the second fluid actuated cylinder and the fluid return path and the second actuated cylinder and the fluid supply path.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrated embodiment exemplifying the best mode of carrying out the invention as presently perceived.